Fatigue in multiple sclerosis: multidimensional assessment and response to symptomatic treatment

Sixty relapsing-remitting multiple sclerosis (MS) patients were selected on the basis of their score on the Fatigue Severity Scale (FSS) and formed two groups: 40 patients (fatigued MS; MSf) scored above the 75th percentile of a previously assessed representative MS sample (100 patients), and 20 age- and sex-matched patients (nonfatigued MS patients; MSnf) scored below the 25th percentile. The patients underwent clinical evaluation (Expanded Disability Status Scale (EDSS)), further assessment of fatigue (Fatigue Impact Scale), scales evaluating depression (Hamilton Depression Rating Scale (HDRS) and Beck’s Depression Inventory (BDI)) and neuropsychological tests. All patients were evaluated for muscle fatigability and central activation by means of a biomechanical test of sustained contraction; they also underwent somatosensory evoked potentials (SSEPs) and transcranial magnetic stimulation (TMS). The patients of the MSf subgroup were then randomized to one of the following two treatments: 4-aminopyridine...